MIAMI (CBSMiami) – A 12-hour swimming relay will raise funds for an 11-year-old boy shot and killed when his father attacked the family then took his own life. Miami kids and teenagers will participate in Saturday’s relay.

Before his death in February, Stefan Zuniga was an avid swimmer for the city of Miami swim team at Shenandoah pool, and his coach, Alexander Urbizagastegui, thought the swimming marathon would be fitting.

Urbizagastegui told CBS4 news partner The Miami Herald that, after the Sandy Hook shooting, he talked to his team about the events, trying to reinforce that school is a safe place.

When Stefan was killed in his own home by his own father, Urbizagastegui found himself struggling for an explanation.

“I saw myself talking to a group of kids … having to explain why no longer one of them is with us,” he said.

Investigators said Carlos Zuniga, 45, shot his wife, Michelle, and their two children before taking his own life outside his Miami home. Zuniga has lost his air balloon ride business and appeared to be unemployed.

Urbizagastegui wanted Stefan’s friends to feel involved in a memorial for the boy, instead of just asking for monetary donations for the family.

Stefan’s mom and sister, Lauren, who were hospitalized for weeks after the incident, are doing much better and should be released soon, Urbizagastegui said.

Urbizagastegui wanted to “help the swimmers cope with the loss and feel like they did something useful … to help, but mainly to feel better inside, that they did something in honor of Stefan for his family,” said of the boy, who attended Coral Way Elementary school.

Agustina Iglesias, 11, who was friend’s with Stefan, said swimming was one of his favorite activities.

“He was a great guy,” she said. “He was really shy, but he loved his family and he loved swimming … He was really sweet and kind.”

She said although the relay will probably be tiring, she wants to “make the best out of it for Stefan.”

Proceeds from the swimming relay at the pool at 1805 SW 22nd Ave, will go to a trust fund for the Zuniga family.